As investigators continue to examine what went wrong with the Martin Olav Sabo Bridge, the city of Minneapolis is looking at options to open the bridge to pedestrian and bike traffic before full repairs are completed.

Could Sabo bridge reopen soon?

Workers this week checks one of the plates on the Martin Olav Sabo Bridge in Minneapolis, which has been closed since Feb. 19. (Staff photo: Bill Klotz)

Engineers may have answer shortly

As investigators continue to examine what went wrong with the Martin Olav Sabo Bridge, the city of Minneapolis is looking at options to open the bridge to pedestrian and bike traffic before full repairs are completed.

“It’s a very popular crossing,” said Heidi Hamilton, the city’s deputy director of public works. “We are looking into that possibility.”

Jack Yuzna, the city’s bridge engineer, said the city wants to see if it is possible to reopen the bridge to bicycles and pedestrians as it is; or if additional shoring is needed; or if it’s feasible at all.

“We anticipate having an answer by [Friday] or Monday,” he said.

On Feb. 19, the bridge was closed after an anchor plate cracked and one of the nine suspension cables that support the bridge’s deck broke. A second pair of cables “was founded to be severely compromised,” according to city documents.

Since then, city and Hennepin County staff members have been working to determine the cause of the failure and stabilize the award-winning $5.1 million cable-stayed bridge, which opened in 2007.

The 2,200-foot-long bridge spans the Hiawatha light rail transit line and Hiawatha Avenue.

The county hired Wiss Janney Elstner Associates, a Chicago-based engineering firm, to inspect the bridge to find out if there are any other “structural issues” and to provide forensic engineering services.

The city and county are splitting the $150,000 cost for engineering services.

WJE began its field work on Feb. 22.

As part of that effort, investigators plan to install instruments on or near the bridge to help monitor the span 24 hours a day, determine what went wrong and formulate plans for repairs.

For example, an anemometer — a fancy name for a wind gauge — will measure wind speeds and direction, and accelerometers will be used to measure vibration, Yuzna said.

The instruments only take about a day or two to install and could be in place within the next week or week and a half, Yuzna said.

Experts will use the data to help with the retrofits of the plates that failed and any other retrofits that may be necessary, he said.

Yuzna said it could take “a few months, at least” to complete the repairs.

Meanwhile, he said, inspectors continue to monitor the bridge’s condition.

“Right now everything is stable, and we are not seeing any problems,” Yuzna said.